The central problem that is addressed by this invention is that of advantageously providing an impregnated fluid stream, metered as to flow rate, for use in a variety of contexts. The production of admixtures of liquids, gases, or a combination of the same, can be troublesome and somewhat expensive. In the past there have been a variety of ways in which this central issue has been addressed. The present invention departs from prior approaches to the problem by utilizing a multi-phasal approach wherein two fluids have a common boundary or juncture such that dispersion across said boundary can be taken advantage of so as to impregnate a fluid in a manner suitable for draw-down and use. Experience with Brownian movement has demonstrated the well-recognized and accepted principle that, for both liquids and gases, there is no quiescent state of matter; rather, molecules in both types of fluids have a substantial kinetic energy and move from place to place. The distance between molecular collisions in liquids, otherwise known as "mean-free path," is small when compared to mean-free path as to gases. In any event, this kinetic energy and the consequential molecular movement is useful, the inventor has found, in impregnating an upper liquid by the substance, components or ions of a lower and heavier liquid enjoying a common boundary with the former liquid. The same applies for gases. Even though gases, especially the lighter gases are said to be miscible, yet for the heavier gases there will be some stratification and some delay in total dispersion of one gas through the other. This can be taken advantage of in impregnating the upper gas with the lower heavier gas for draw-down as circumstances warrant. In a particular application, a fundamental thrust of the invention is in the maintenance of hygienic water in a swimming pool wherein chlorine or another halogen is employed as a sterilizing agent. Halogens are, of course, the five elements, fluorine, chlorine, bromine, iodine and astatine forming group 7A in the periodic table. These exist, of course, in a free state normally as diatomic molecules. Various types of chemicals are extant and readily available for use. These are all biocides and can be used essentially detoxifying by biocidal action swimming pool water, waste effluent, and so on. As to one use of the invention, i.e., the treatment of swimming pool water, chlorine remains a preferred sterilizing agent.
In order to limit the growth of bacteria and algae in swimming pool water, to maintain hygienic water in the pool, chlorine is conventionally used as the sterilizing agent. In professionally maintained pools, gaseous chlorine is used as the sterilizing agent. Gaseous chlorine is cheap, but is toxic, and thus is not generally distributed to the public for use in their swimming pools.
Chlorine remains the preferred sterilizing agent, but is supplied to the custodians of small pools in forms where it is combined with other material so that the chlorine is released when the compound is placed in the swimming pool. Several solid compounds are available, but each has a disadvantage. The most commonly employed material in the sterilization of swimming pools is sodium hypochlorite in about 90 percent water solution. One of the disadvantages of this material is that the release of chlorine is too fast, with a consequence that the amount of dissolved chlorine in the swimming pool declines due to dissipation of free chlorine from the pool surface. When the sodium hypochlorite solution is poured directly into the pool, there is no reserve to further supply chlorine to the pool water. Another disadvantage of the employment of a water solution of sodiuim hypochlorite as the supplier of chlorine to the swimming pool water is that one of the dissociation products is sodium chloride. This sodium chloride eventually builds up in the pool water until the pool water has a salty taste and must be changed.
Thus, there is need for a swimming pool chlorinator which employes the conveniently available water solution of sodium hypochlorite as the source of chlorine, but which provides ongoing release of the water solution of chlorine gas to the pool, together with means for retaining a substantial amount of sodium chloride separate from the pool water. It will be understood that rather than using sodium hypochlorite, any one of a number of chemicals can be employed for the treatment of swimming pool water as, for example, such as any one of a number of halide salts that can be in combination with sodium, for example. There are likewise calcium salts in connection with the above-designated halogens.
As to the basic concept of utilizing diffusion to provide a metered, impregnated outflow, no applicable art is now known to the inventor. In connection with swimming pool maintenance, however, the following U.S. Pat. Nos. are known: 4,303,515, 2,984,250, 4,333,833, 3,672,508, 4,363,728, 4,067,808, 4,381,240.
U.S. Pat. No. 2,984,250 teaches a water treatment system, relying, not upon a cross-boundary diffusion as in the present invention, but rather upon the use of a membrane between main-line water and a chemical solution that is employed.
U.S. Pat. No. 3,672,508 teaches a swimming pool chlorinator wherein an injection system is employed to introduce chlorine into the pool. The chlorine tank employed had a float valve.
U.S. Pat. No. 4,067,808 teaches a chlorinator for a swimming pool but where a physical solid separator is employed in the tank, and wherein chlorine introduction is based upon the weight of the water above the separator in forcing the chlorine solution downwardly and from there upwardly through a stand pipe.
U.S. Pat. No. 4,303,515 indicates a standard chemical dispenser employing chlorination tablets in combination with a water injection system.
U.S. Pat. No. 4,333,833 simply indicates an in-line disinfectant contactor having a side ranch chlorinator.
U.S. Pat. No. 4,363,728 teaches the employment of an automatic chlorinator for swimming pools; however, no diffusion principle is employed therein.
U.S. Pat. No. 4,381,240 indicates a swimming pool conditioning system wherein a manifold is employed to collect chlorine gas liberated by electrolysis whereby to introduce chlorinated water back to a swimming pool.
In none of these patents is there taught the principle of utilizing diffusion across the common unobstructed boundary of two fluids for impregnating an upper fluid of lower density, specific gravity, or molecular weight whereby to draw off a metered flow of such impregnated fluid for future use, whether for swimming pools or otherwise.